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1.
Acta Pharmacol Sin ; 45(4): 803-814, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38172305

RESUMEN

Overactivation of the NLRP3 inflammasomes induces production of pro-inflammatory cytokines and drives pathological processes. Pharmacological inhibition of NLRP3 is an explicit strategy for the treatment of inflammatory diseases. Thus far no drug specifically targeting NLRP3 has been approved by the FDA for clinical use. This study was aimed to discover novel NLRP3 inhibitors that could suppress NLRP3-mediated pyroptosis. We screened 95 natural products from our in-house library for their inhibitory activity on IL-1ß secretion in LPS + ATP-challenged BMDMs, found that Britannin exerted the most potent inhibitory effect with an IC50 value of 3.630 µM. We showed that Britannin (1, 5, 10 µM) dose-dependently inhibited secretion of the cleaved Caspase-1 (p20) and the mature IL-1ß, and suppressed NLRP3-mediated pyroptosis in both murine and human macrophages. We demonstrated that Britannin specifically inhibited the activation step of NLRP3 inflammasome in BMDMs via interrupting the assembly step, especially the interaction between NLRP3 and NEK7. We revealed that Britannin directly bound to NLRP3 NACHT domain at Arg335 and Gly271. Moreover, Britannin suppressed NLRP3 activation in an ATPase-independent way, suggesting it as a lead compound for design and development of novel NLRP3 inhibitors. In mouse models of MSU-induced gouty arthritis and LPS-induced acute lung injury (ALI), administration of Britannin (20 mg/kg, i.p.) significantly alleviated NLRP3-mediated inflammation; the therapeutic effects of Britannin were dismissed by NLRP3 knockout. In conclusion, Britannin is an effective natural NLRP3 inhibitor and a potential lead compound for the development of drugs targeting NLRP3.


Asunto(s)
Inflamasomas , Lactonas , Proteína con Dominio Pirina 3 de la Familia NLR , Sesquiterpenos , Animales , Humanos , Ratones , Inflamasomas/agonistas , Interleucina-1beta/metabolismo , Lactonas/farmacología , Lactonas/uso terapéutico , Lipopolisacáridos/farmacología , Macrófagos , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/antagonistas & inhibidores , Sesquiterpenos/farmacología , Sesquiterpenos/uso terapéutico
2.
Molecules ; 29(7)2024 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-38611728

RESUMEN

The epidermal growth factor receptor (EGFR) plays a pivotal role in cancer therapeutics, with small-molecule EGFR inhibitors emerging as significant agents in combating this disease. This review explores the synthesis and clinical utilization of EGFR inhibitors, starting with the indispensable role of EGFR in oncogenesis and emphasizing the intricate molecular aspects of the EGFR-signaling pathway. It subsequently provides information on the structural characteristics of representative small-molecule EGFR inhibitors in the clinic. The synthetic methods and associated challenges pertaining to these compounds are thoroughly examined, along with innovative strategies to overcome these obstacles. Furthermore, the review discusses the clinical applications of FDA-approved EGFR inhibitors such as erlotinib, gefitinib, afatinib, and osimertinib across various cancer types and their corresponding clinical outcomes. Additionally, it addresses the emergence of resistance mechanisms and potential counterstrategies. Taken together, this review aims to provide valuable insights for researchers, clinicians, and pharmaceutical scientists interested in comprehending the current landscape of small-molecule EGFR inhibitors.


Asunto(s)
Carcinogénesis , Transformación Celular Neoplásica , Humanos , Afatinib , Receptores ErbB , Clorhidrato de Erlotinib
3.
Phys Chem Chem Phys ; 25(37): 25435-25441, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37706505

RESUMEN

Aqueous Zn-ion batteries (AZIBs) have become one of the most promising energy storage devices due to their high safety and low cost. However, the development of stable cathodes with fast kinetics and high energy density is the key to achieving large-scale application of AZIBs. In this work, W-doped VO2 (W-VO2) is developed by a one-step hydrothermal method. Benefiting from the pre-insertion of W6+ and the introduction of the W-O bond, accomplishing an expanded lattice spacing and a stable structure, both improved kinetics and long cycle life are achieved. The W-VO2 delivers a specific capacity of 340.2 mA h g-1 at 0.2 A g-1, an excellent high-rate capability with a discharge capacity of 186.9 mA h g-1 at 10 A g-1, and long-term cycling stability with a capacity retention of 76.5% after 2000 cycles. The electrochemical performance of the W-VO2 has been greatly improved, compared with the pure VO2. The W doping strategy proposed here also presents an encouraging pathway for developing other high-energy and stable cathodes.

4.
J Nat Prod ; 86(12): 2718-2729, 2023 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-38081625

RESUMEN

Neuronal cell damage is a major cause of cognitive impairment in Alzheimer's disease (AD). Multiple factors, such as amyloid deposition, tau hyperphosphorylation, and neuroinflammation, can lead to neuronal cell damage. Therefore, the development of multi-target drugs with broad neuroprotective effects may be an effective strategy for the treatment of AD. Natural products have become an important source of drug discovery because of their good pharmacological activity, multiple targets, and low toxicity. In this study, we screened a natural compound library and found that the fat-soluble sesquiterpene natural compound isolinderalactone (Iso) extracted from the dried root pieces of Lindera aggregata had the ability to alleviate cellular damage induced by ß-amyloid-1-42 (Aß1-42). The role and mechanism of Iso in AD have not yet been reported. Herein, we demonstrated that Iso significantly reduced the level of apoptosis in PC12 cells. Besides, Iso treatment reduced amyloid deposition, neuron apoptosis, and neuroinflammation, ultimately improving the cognitive dysfunction of APP/PS1 (APPswe/PSEN 1dE9) mice. Notably, Iso-10 mg/kg showed superior improved effects in APP/PS1 mice compared with the positive control drug donepezil-5 mg/kg. Mechanistically, the results of RNA sequencing combined with Western blots showed that Iso exerted its therapeutic effect by inhibiting the c-Jun N-terminal kinase (JNK) signaling pathway. Taken together, our findings suggest that Iso is a potential drug candidate for the treatment of AD.


Asunto(s)
Enfermedad de Alzheimer , Sesquiterpenos , Ratas , Ratones , Animales , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Enfermedades Neuroinflamatorias , Ratones Transgénicos , Péptidos beta-Amiloides , Sesquiterpenos/farmacología , Sesquiterpenos/uso terapéutico , Modelos Animales de Enfermedad , Precursor de Proteína beta-Amiloide/metabolismo
5.
Sensors (Basel) ; 23(20)2023 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-37896726

RESUMEN

Variations with respect to perspective, lighting, weather, and interference from dynamic objects may all have an impact on the accuracy of the entire system during autonomous positioning and during the navigation of mobile visual simultaneous localization and mapping (SLAM) robots. As it is an essential element of visual SLAM systems, loop closure detection plays a vital role in eradicating front-end-induced accumulated errors and guaranteeing the map's general consistency. Presently, deep-learning-based loop closure detection techniques place more emphasis on enhancing the robustness of image descriptors while neglecting similarity calculations or the connections within the internal regions of the image. In response to this issue, this article proposes a loop closure detection method based on similarity differences between image blocks. Firstly, image descriptors are extracted using a lightweight convolutional neural network (CNN) model with effective loop closure detection. Subsequently, the image pairs with the greatest degree of similarity are evenly divided into blocks, and the level of similarity among the blocks is used to recalculate the degree of the overall similarity of the image pairs. The block similarity calculation module can effectively reduce the similarity of incorrect loop closure image pairs, which makes it easier to identify the correct loopback. Finally, the approach proposed in this article is compared with loop closure detection methods based on four distinct CNN models with a recall rate of 100% accuracy; said approach performs significantly superiorly. The application of the block similarity calculation module proposed in this article to the aforementioned four CNN models can increase the recall rate's accuracy to 100%; this proves that the proposed method can successfully improve the loop closure detection effect, and the similarity calculation module in the algorithm has a certain degree of universality.

6.
Angew Chem Int Ed Engl ; 62(11): e202216155, 2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36653894

RESUMEN

High voltage can cost-effectively boost energy density of Ni-rich cathodes based Li-ion batteries (LIBs), but compromises their mechanical, electrochemical and thermal-driven stability. Herein, a collaborative strategy (i.e., small single-crystal design and hetero-atom doping) is devised to construct a chemomechanically reliable small single-crystal Mo-doped LiNi0.6 Co0.2 Mn0.2 O2 (SS-MN6) operating stably under high voltage (≥4.5 V vs. Li/Li+ ). The substantially reduced particle size combined with Mo6+ doping absorbs accumulated localized stress to eradicate cracks formation, subdues the surface side reactions and lattice oxygen missing meanwhile, and improves thermal tolerance at highly delithiated state. Consequently, the SS-MN6 based pouch cells are endowed with striking deep cycling stability and wide-temperature-tolerance capability. The contribution here provides a promising way to construct advanced cathodes with superb chemomechanical stability for next-generation LIBs.

7.
Fish Shellfish Immunol ; 128: 181-187, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35917888

RESUMEN

The present study aimed to examine the effects of short-term exposure to ammonia on stress and oxidative responses in shrimp (Litopenaeus vannamei) and to determine whether the antioxidant system related to the regulatory role of transcription factors and stress proteins was activated. Shrimp were exposed ammonia-N at four concentrations: 0 (control), 5, 10, and 15 mg/L, for 48 h. The hepatopancreas was sampled to measure the levels of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO); the activities of superoxide dismutase (SOD), catalase (CAT), nitric oxide synthase (NOS); and the expression levels of GSH-px (encoding glutathione peroxidase), GST (encoding glutathione-S-transferase), HSP70 (encoding heat shock protein 70), HSP90 (encoding heat shock protein 90), p53, RELISH, and AKIRIN. We observed that exposure to a high ammonia content increased the abundance of oxidative factors (MDA, CAT, SOD, NOS, and NO), reduced the levels of GSH, and upregulated the mRNA expression levels of antioxidant genes (GSH-px and GST), stress-related genes (HSP70 and HSP90), and transcription factor genes (p53, RELISH, and AKIRIN). These results indicated that ammonia induced oxidative stress and inflammation. Both enzymatic and nonenzymatic antioxidant defense systems are involved, which might be regulated by HSPs, as well as certain transcription factors, such as p53 and nuclear factor kappa B (NF-κB), thus mounting an adaptive response to help rebalance redox homoeostasis.


Asunto(s)
Amoníaco , Penaeidae , Amoníaco/metabolismo , Amoníaco/toxicidad , Animales , Antioxidantes/metabolismo , Catalasa/metabolismo , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Respuesta al Choque Térmico , Malondialdehído/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico/metabolismo , Oxidación-Reducción , Estrés Oxidativo , ARN Mensajero/metabolismo , Superóxido Dismutasa/metabolismo , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/metabolismo
8.
Chem Biodivers ; 19(7): e202200294, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35594039

RESUMEN

The two novel polysaccharides, DMP-1 and DMP-2, with molecular weights of 4.1553×105  kDa and 1.9764×105  kDa, respectively, were isolated from Dracocephalum moldavica. The structural characterization indicated that DMP-1 and DMP-2 shared a similar backbone consisting of →5)-Araf-(1→, Manp-(1→, Glcp-(1→, →2)-Manp-(1→, →6)-Glcp-(1→ and →3,6)-Galp-(1→ with a different molar ratios and triple-helix structures with α- and ß-type glycosidic bonds. The anti-complementary activity evaluation showed that DMP-1 and DMP-2 had strong complement inhibition through the classical pathway (CP), alternative pathway (AP) and lectin pathway (LP). Mechanistic studies indicated that DMP-1 can block the activation cascade of the complement system by targeting C2, C3, C5, C9, Factor B and Factor P, and that DMP-2 inhibited complement activation by blocking C2, C3, C4, C5, C9 and Factor B.


Asunto(s)
Factor B del Complemento , Lamiaceae , Activación de Complemento , Polisacáridos/química
9.
Chem Biodivers ; 19(8): e202200525, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35841390

RESUMEN

The polysaccharides from the rhizomes of Belamcanda chinensis (L.) DC. (BCPs) were obtained by optimal water extraction (extraction temperature 84 °C, liquid to solid ratio 42 mL/g and extraction time 100 min), the extraction yield of BCPs was 23.01±0.27 % (n=3). Furthermore, two novel polysaccharides (BCP-A1 and BCP-B1) were purified by column chromatography. The BCP-A1 (6.0820×104  kDa) was composed of ß-D-Manp-(1→, ß-D-Glcp-(1→, →4)-α-D-Galp-(1→ and →3,4)-ß-D-Galp-(1→, and BCP-B1 (2.2744×104  kDa) was composed of →5)-α-L-Araf-(1→, ß-D-Manp-(1→, ß-D-Glcp-(1→, →4)-α-D-Glcp, →4)-α-D-Galp-(1→, →4)-α-D-GalpA-(1→ and →3,4)-ß-D-Galp-(1→. In anticomplementary experiments, BCP-A1 (CH50 : 0.009±0.003 mg/mL; AP50 : 0.015±0.003 mg/mL) and BCP-B1 (CH50 : 0.004±0.001 mg/mL; AP50 : 0.028±0.005 mg/mL) exhibited potent anticomplementary activity, and acted on C2-, C4- and Factor B components. Our study provides a foundation for BCP-A1 and BCP-B1 as potential complement inhibitors to treat diseases involving with excessive activation of the complement system.


Asunto(s)
Polisacáridos , Rizoma , Proteínas del Sistema Complemento , Polisacáridos/química , Polisacáridos/farmacología , Rizoma/química
10.
J Asian Nat Prod Res ; 24(12): 1177-1184, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35001746

RESUMEN

One novel naphthalene derivative, 2-octa-2',4',6'-atriynenaphthalene (1), together with eighteen known compounds (2-19) were isolated from the aerial parts of Dracocephalum moldavica L. Compounds 2, 8, 10, 13, 15-17 and 19 were obtained from the family Lamiaceae for the first time, and compounds 11 and 18 were firstly identified from the genus of Dracocephalum. All the isolates were evaluated for anti-complementary activities through the classical and alternative pathways, and the targets of the most active compounds on the complement activation cascade were also investigated.


Asunto(s)
Lamiaceae , Estructura Molecular , Componentes Aéreos de las Plantas , Naftalenos/farmacología
11.
J Asian Nat Prod Res ; 24(9): 849-859, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34657548

RESUMEN

Twelve novel cordycepin derivatives were designed and synthesized with modification at positions of 2', 5'-hydroxyl and N6 amino groups of cordycepin. The results showed that the inhibitory activities of 3, 4b, 6c and 6d on A549 were comparable to the positive control gefitinib, and the inhibitory activity of 6a on A549 was better than that of gefitinib. Also, the inhibitory activities of twelve cordycepin derivatives against E. coli 1924, S. aureus 4220 and S. mutans 3289 were studied. Among them, 4b showed certain inhibitory on S. mutans 3289, while 6b showed certain inhibition on S. aureus 4220.


Asunto(s)
Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacología , Desoxiadenosinas , Gefitinib , Estructura Molecular , Relación Estructura-Actividad
12.
J Asian Nat Prod Res ; 24(1): 31-38, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33502248

RESUMEN

Two new phenolic glycosides (1-2) and eleven known compounds (3-13) were isolated from the fruits of Illicium verum Hook.f. using silica-gel column and preparative middle pressure liquid chromatography (MPLC). The structures of the compounds were elucidated by NMR spectroscopic data. Among them, compounds 3, 5, and 10 were isolated from the family Magnoliaceae for the first time. Additionally, all the compounds were evaluated for their anti-complementary activities against the classical pathway (CP) and the alternative pathway (AP).


Asunto(s)
Illicium , Frutas , Glicósidos/farmacología , Estructura Molecular , Fenoles/farmacología
13.
J Asian Nat Prod Res ; 24(8): 746-753, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35137660

RESUMEN

Two new stilbene glucosides, trans-3,5-dihydroxy-4-methoxystilbene 3-O-ß-D-glucopyranoside (1), cis-3,5-dihydroxy-4-methoxystilbene 3-O-ß-D-glucopyranoside (2), one new benzoic acid derivative, cis-4-hydroxy-3-hydroxymethyl-2-butenyl benzoate 4-O-ß-D-glucopyranoside (3), and four known compounds (4 - 7) were isolated from Tournefortia sibirica L. The structures of these compounds were elucidated on the basis of spectral data. Anti-inflammatory effects of compounds (1 - 7) were evaluated in terms of inhibition on production of NO, TNF-α and IL-6 in LPS-induced RAW 264.7 cells. Compounds 1, 2 and 5 - 7 could inhibit the levels of NO, TNF-α and IL-6 in LPS-induced RAW264.7 cells with IC50 values ranging from 40.96 to 88.76 µM.


Asunto(s)
Boraginaceae , Estilbenos , Ácido Benzoico/farmacología , Glucósidos/química , Glucósidos/farmacología , Interleucina-6 , Lipopolisacáridos/farmacología , Estructura Molecular , Estilbenos/química , Estilbenos/farmacología , Factor de Necrosis Tumoral alfa
14.
Eur J Nutr ; 60(5): 2855-2875, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33555375

RESUMEN

PURPOSE: Probiotics have been reported to be beneficial for inflammatory bowel disease (IBD), but the types, number of strains, dosage, and intervention time of probiotics used remain controversial. Furthermore, the changes of gut microbiota in IBD's patients are also intriguing. Thus, this meta-analysis was to explore the clinical effects and gut microbiota changes of using probiotics, prebiotics and synbiotics in IBD. METHODS: The search was performed in PubMed, Web of Science and the Cochrane library from inception to April 2020. Qualified randomized controlled trials were included. IBD's remission rate, disease activity index and recurrence rate were extracted and analyzed. Changes in the gut microbiota of patients with IBD are comprehensively described. RESULTS: Thirty-eight articles were included. Probiotics, prebiotics and synbiotics can induce/maintain IBD's remission and reduce ulcerative colitis (UC) disease activity index (RR = 1.13, 95% CI 1.02, 1.26, P < 0.05; SMD = 1.00, 95% CI 0.27, 1.73, P < 0.05). In subgroup analyses of IBD remission rate and UC disease activity index, we obtained some statistically significant results in some subgroup (P < 0.05). To some extent, probiotic supplements can increase the number of beneficial bacteria (especially Bifidobacteria) in the intestinal tract of patients with IBD. CONCLUSIONS: Our results support the treatment of IBD (especially UC) with pro/pre/synbiotics, and synbiotics are more effective. Probiotic supplements that are based on Lactobacillus and Bifidobacterium or more than one strain are more likely to be beneficial for IBD remission. The dose of 1010-1012 CFU/day may be a reference range for using probiotics to relieve IBD.


Asunto(s)
Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Probióticos , Simbióticos , Humanos , Enfermedades Inflamatorias del Intestino/terapia , Prebióticos
15.
Angew Chem Int Ed Engl ; 59(6): 2473-2482, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-31793139

RESUMEN

Ultrathin core-shell V3 S4 @C nanosheets assembled into hierarchical nanotubes (V3 S4 @C NS-HNTs) are synthesized by a self-template strategy and evaluated as general anodes for alkali-ion batteries. Structural/physicochemical characterizations and DFT calculations bring insights into the intrinsic relationship between crystal structures and electrochemical mechanisms of the V3 S4 @C NS-HNTs electrode. The V3 S4 @C NS-HNTs are endowed with strong structural rigidness owing to the layered VS2 subunits and interlayer occupied V atoms, and efficient alkali-ion adsorption/diffusion thanks to the electroactive V3 S4 -C interfaces. The resulting V3 S4 @C NS-HNTs anode exhibit distinct alkali-ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in storage of K+ , benefiting from synergistic contributions of pseudocapacitive and reversible intercalation/de-intercalation behaviors superior to those of the conversion-reaction-based Li+ -/Na+ -storage counterparts.

16.
Microb Cell Fact ; 17(1): 66, 2018 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-29720171

RESUMEN

BACKGROUND: Lignocellulosic ethanol could offer a sustainable source to meet the increasing worldwide demand for fuel. However, efficient and simultaneous metabolism of all types of sugars in lignocellulosic hydrolysates by ethanol-producing strains is still a challenge. RESULTS: An engineered strain Escherichia coli B0013-2021HPA with regulated glucose utilization, which could use all monosaccharides in lignocellulosic hydrolysates except glucose for cell growth and glucose for ethanol production, was constructed. In E. coli B0013-2021HPA, pta-ackA, ldhA and pflB were deleted to block the formation of acetate, lactate and formate and additional three mutations at glk, ptsG and manZ generated to block the glucose uptake and catabolism, followed by the replacement of the wild-type frdA locus with the ptsG expression cassette under the control of the temperature-inducible λ pR and pL promoters, and the final introduction of pEtac-PA carrying Zymomonas mobilis pdc and adhB for the ethanol pathway. B0013-2021HPA was able to utilize almost all xylose, galactose and arabinose but not glucose for cell propagation at 34 °C and converted all sugars to ethanol at 42 °C under oxygen-limited fermentation conditions. CONCLUSIONS: Engineered E. coli strain with regulated glucose utilization showed efficient metabolism of mixed sugars in lignocellulosic hydrolysates and thus higher productivity of ethanol production.


Asunto(s)
Escherichia coli/metabolismo , Etanol/metabolismo , Glucosa/metabolismo , Lignina/metabolismo
17.
Biotechnol Lett ; 40(5): 781-788, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29564679

RESUMEN

OBJECTIVES: To develop a xylose-nonutilizing Escherichia coli strain for ethanol production and xylose recovery. RESULTS: Xylose-nonutilizing E. coli CICIM B0013-2012 was successfully constructed from E. coli B0013-1030 (pta-ack, ldhA, pflB, xylH) by deletion of frdA, xylA and xylE. It exhibited robust growth on plates containing glucose, arabinose or galactose, but failed to grow on xylose. The ethanol synthesis pathway was then introduced into B0013-2012 to create an ethanologenic strain B0013-2012PA. In shaking flask fermentation, B0013-2012PA fermented glucose to ethanol with the yield of 48.4 g/100 g sugar while xylose remained in the broth. In a 7-l bioreactor, B0013-2012PA fermented glucose, galactose and arabinose in the simulated corncob hydrolysate to 53.4 g/l ethanol with the yield of 48.9 g/100 g sugars and left 69.6 g/l xylose in the broth, representing 98.6% of the total xylose in the simulated corncob hydrolysate. CONCLUSIONS: By using newly constructed strain B0013-2012PA, we successfully developed an efficient bioprocess for ethanol production and xylose recovery from the simulated corncob hydrolysate.


Asunto(s)
Escherichia coli/crecimiento & desarrollo , Etanol/metabolismo , Xilosa/química , Zea mays/química , Técnicas de Cultivo Celular por Lotes , Reactores Biológicos/microbiología , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentación , Ingeniería Genética , Glucosa/metabolismo , Hidrólisis
18.
Molecules ; 23(1)2018 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-29361681

RESUMEN

This paper calculates the potential energy curves of the 14 Λ-S and 49 Ω states, which come from the first three dissociation channels of the SiN- anion. These calculations are conducted using the valence internally contracted multireference configuration interaction and the Davidson correction approach. Core-valence correlation and scalar relativistic corrections are taken into account. The potential energies are extrapolated to the complete basis set limit. The spin-orbit coupling is computed using the state interaction approach with the Breit-Pauli Hamiltonian. We found that the X¹Σ⁺ (υ'' = 0-23) and a³Σ⁺ (υ' = 0-2) states of SiN- are stable at the computed adiabatic electron affinity value of 23,262.27 cm-1 for SiN. Based on the calculated potential energy curves, the spectroscopic parameters and vibrational levels were determined for all stable and metastable Λ-S and Ω states. The computed adiabatic electron affinity of SiN and the spectroscopic constants of SiN- (X¹Σ⁺) are all in agreement with the available experimental data. The d³Σ⁺, 25Σ⁺, 15Δ, and 15Σ- quasi-bound states caused by avoided crossings were found. Calculations of the transition dipole moment of a³Σ⁺1 to X¹Σ⁺0+ are shown. Franck-Condon factors, Einstein coefficients, and radiative lifetimes of the transition from the a³Σ⁺1 (υ' = 0-2) to the X¹Σ⁺0+ state are evaluated.


Asunto(s)
Gases/química , Modelos Moleculares , Fenómenos Físicos , Compuestos de Silicona/química , Aniones/química , Electrones , Teoría Cuántica , Análisis Espectral/métodos , Termodinámica , Vibración
19.
Small ; 13(45)2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28941073

RESUMEN

Recently, wearable electronic devices including electrical sensors, flexible displays, and health monitors have received considerable attention and experienced rapid progress. Wearable supercapacitors attract tremendous attention mainly due to their high stability, low cost, fast charging/discharging, and high efficiency; properties that render them value for developing fully flexible devices. In this Concept, the recent achievements and advances made in flexible and wearable supercapacitors are presented, especially highlighting the promising performances of yarn/fiber-shaped and planar supercapacitors. On the basis of their working mechanism, electrode materials including carbon-based materials, metal oxide-based materials, and conductive polymers with an emphasis on the performance-optimization method are introduced. The latest representative techniques and active materials of recently developed supercapacitors with superior performance are summarized. Furthermore, the designs of 1D and 2D electrodes are discussed according to their electrically conductive supporting materials. Finally, conclusions, challenges, and perspective in optimizing and developing the electrochemical performance and function of wearable supercapacitors for their practical utility are addressed.

20.
J Phys Chem A ; 121(43): 8207-8216, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-28994291

RESUMEN

This work investigates the spectroscopic parameters, vibrational levels, and transition probabilities of 12 low-lying states, which are generated from the first dissociation limit, Br(2Pu) + O-(2Pu), of the BrO- anion. The 12 states are X1Σ+, 21Σ+, 11Σ-, 11Π, 21Π, 11Δ, a3Π, 13Σ+, 23Σ+, 13Σ-, 23Π, and 13Δ. The potential energy curves are calculated with the complete active-space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with Davidson modification. The dissociation energy D0 of X1Σ+ state is determined to be approximately 26876.44 cm-1, which agrees well with the experimental one of 26494.50 cm-1. Of these 12 states, the 21Σ+, 11Σ-, 21Π, 11Δ, 13Σ+, 23Σ+, 23Π, and 13Δ states are very weakly bound states, whose well depths are only several-hundred cm-1. The a3Π, 23Π, and 13Δ states are inverted and account for the spin-orbit coupling effect. No states are repulsive regardless of whether the spin-orbit coupling effect is included. The spectroscopic parameters and vibrational levels are determined. The transition dipole moments of 12-pair electronic states are calculated. Franck-Condon factors of a number of transitions of more than 20-pair electronic states are evaluated. The electronic transitions are discussed. The spin-orbit coupling effect on the spectroscopic parameters and vibrational properties is profound for all the states except for X1Σ+, a3Π, and 11Π. The spectroscopic parameters and transition probabilities obtained in this paper can provide some powerful guidelines for observing these states in a proper spectroscopy experiment, in particular the states that have very shallow potential wells.

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